Thermal behaviour of five different date palm residues of algeria by thermogravimetric analysis

Renewable energy has become more important globally especially with the current fuel and economic crisis. Date palm biomasses are highly potential materials for energy resources. The fact that they are renewable and abundantly available are amongst the attractive reasons of employing them as the major source for renewable energy. The purpose of this research was to investigate the thermal behavior of date palm biomass in order to evaluate their usefulness for energy production. In microparticular scale, the thermogravimetric analysis (TGA) is one of the techniques used to determine the thermal properties of five different date palm residues that were studied: (date palm rachis (DPR), date palm trunk (DPT), leaf base (Petiole) (LB), fruitstalk prunings (FP) and liff (LP)). The TGA technique consists to record the lost weight during the increase in temperature from 20°C until 600°C with a 10°C/min heating rate. The thermograms presented a departure phase of free water (from room temperature to 110°C) before the degradation process of the lignocellulosic constituents. The lignin and hemicellulose play an important role on the degradation of lignocellulosic materials at the temperature under 250°C. The degradation of cellulose begins at 250°C and overlaps to that of lignin until 450°

Variation of shear properties of welded spruce at different pressures and welding times

International audienceThis work presents a study of mechanical properties of the wood end-grain welding of spruce wood. The shear properties of butt joints of spruce at different pressure and welding time were studied.Between all the parameters of spruce welding, the welding pressure is one of the most important in relation to the mechanical properties. Thus, a good joint strength was obtained for spruce wood at high pressure. An increase of shear strength is observed with an increase in welding pressure. It is clear that at high pressure the welded material becomes more rigid and this is also coupled to the to the more extensive condensation reaction of lignin.The defibration tendency in end-grain-to-end-grain welding indicates that wood spruce welding is possible and yields sufficient joint strength. The welded interphase in end-grain-to-end-grain spruce welding appears possible and gives a joint with an anatomical appearance of a “natural” fingerjoint. Such “natural” fingerjoints can give equivalent than glued fingerjoints.The advantages of the end-grain-to-end-grain welding are then the very short time of processing, the dispensation of preparing the fingerjoint profiles and to avoid the use of adhesives

Optimization of Wood Welding Parameters for Australian Hardwood Species

Optimal linear wood welding parameters along the end-grain-to-end-grain faces were determined for Eucalyptus saligna, Eucalyptus pilularis, and Corymbia maculata. Joints made using Eucalyptus saligna showed a significant interaction between welding time (WT), amplitude (WA), and pressure (WP). A preheating phase of 3 s at 0.4 MPa WP and 0.75 mm WA coupled with a WT of 2 s at 2.0 MPa WP and 1.5 mm WA provided the best shear strength results of 5.1 MPa. Joints made using Eucalyptus pilularis and Corymbia maculata snapped once the holding pressure was removed, suggesting that end-grain-to-end-grain welded fibers cannot withstand the thermal stresses generated when the surface to be welded is too small (e.g., 13.5 cm2). However, grain orientation had a significant effect on the weld mechanical properties, as very strong edge-grain-to-edge-grain joints were produced with Eucalyptus pilularis and Corymbia maculata (9.5 and 6.2 MPa, respectively). The joints made of Eucalyptus saligna also showed significant improvement (7.3 MPa). Energy efficient combinations were usually those involving low WA and short WT, as WP had a marginal effect on energy consumption

Effects of corona discharge treatment on the mechanical properties of biocomposites from polylactic acid and Algerian date palm fibres

In this paper, biocomposites materials based on date palm fibres (untreated or treated with corona discharge) as reinforcing elements and polylactic acid matrices were prepared and characterized. The objective of this study was to evaluate the mechanical properties of these biocomposites by modification of date palm fiber by using corona discharge treatment which results in a surface oxidation. The morphology of processed biocomposites was studied by scanning electron microscopy. It was found that treated fibers of the reinforced composite showed superior mechanical properties as compared with untreated fiber reinforced composites due to the enhanced adhesion between the treated date palm fiber and the polylactic acid matrix. Changes in the surface chemistry were investigated with Fourier Transform infrared spectroscopy. Moreover, morphological studies by scanning electron microscopy demonstrated that better adhesion between the treated fiber and the matrix was achieved. Such studies are of great interest in the development of environmentally friendly composites from biodegradable polymer

Particleboards production from date palm biomass

Date palm biomass is a renewable natural resource that has not widely been utilized in industry. The objective of this study was to examine some chemical properties of date palm trunk and rachis (holocellulose, cellulose, lignin and extractives) and to evaluate their suitability to produce composite panels. Particleboards were produced using trunk and rachis as an alternative raw material for forest products industry in the presence of two types of polycondensation resins (phenol–formaldehyde and melamine urea–formaldehyde) which were selected as binding agents. The panels were tested for their physical (water absorption and thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bond strength) properties. The internal bond strength of date palm trunk and date palm rachis based boards met the requirements of the general purpose product standards (EN 312) at 0.70 g/cm3 density. The panels made with phenol–formaldehyde resin showed better performance with respect to the panels made with melamine urea–formaldehyde. In addition, the particleboard made with date palm trunk particles had better quality compared to the particleboard made from date palm rachis particles. Based on preliminary results of this work, raw materials from date palm trunks and rachis can have a promising potential in the manufacture of particleboards and as a substitute for wood in board productio

Rematerializing Tourism Studies: Toward a Political Economy of Tourist Space

International audienc